1. Field of the Invention
The present invention relates to a solid-state image pickup device.
2. Description of the Related Art
Heretofore there has been a problem that video cameras have used a lens aperture or electronic shutter to control the luminous energy of incident light, whereby it is impossible to control the luminous energy of the incident light in one picture element unit, and when an intense light is present locally in an image pickup plane, brume occurs at the point by the excessive luminous energy or an entire image plane becomes remarkably dark because of excessive backlight correction, that is, excessive luminous energy reduces backlight condition by excessive stopping down of the iris (cf. U.S. Pat. No. 5,047,847). Thus, the luminous energy of incident light must be controlled in each pixel in order to solve the problem. And a technique of controlling the energy in each pixel is known (cf. Japanese Laid-open Patent No. 1988/35081).
However, the prior art has a problem in that a system in which a feedback loop is formed over two or more frames/fields, an external circuit for feedback loop is necessary, and in addition, a time shift of at least one frame occurs unavoidably between the frame/field of detecting the luminous energy of incident light and the frame/field of feedback destination. The prior art cannot deal with a high speed moving luminous body, and needs the external circuit, thereby preventing the miniaturization of video cameras.
Thus, a solid-state image pickup element becomes necessary in which the luminous energy of incident light is corrected in one pixel for miniaturization, and a feedback loop is formed in the same frame/field for a high speed feedback.
The present invention is made to solve such problems of the above prior art solid-state image pickup devices, and it is an object of the invention to provide a solid-state image pickup device which has a luminous energy correcting function for reducing incident light transmission (ratio) in one pixel during the same frame/field even if an intense light occurs locally on any place of an image plane, and makes it possible to improve the MTF(modulation transfer function) by restricting an area of the incident light transmission reduction to a part of the photo-electric transfer area, thereby making the open area of the photo-electric transfer area narrow.